I am an undergraduate control and system engineer undergraduate. I had previous interest in mathematics, but now I want to study pure mathematics in conjunction with control engineering. It would be better for me if the pure math courses are related to control and systems. So what are the areas that will be most relevant to my control engineering major? I wanted to note that my control and system major involves numerous communications courses and I have taken the calculus and differential equations courses, up till now, in my engineering major.